Hello;
it smells like a hack attempt.
Try to go to you PHPMyAdmin, and open your database.
Search for the 4images_settings table.
Search the field allowed_mediatypes, and change its value to:
jpg,gif,png,aif,au,avi,mid,mov,mp3,mpg,swf,wav,ra,rm,zip,pdf
If you have kept your database prefix as 4images, you can instead try to import the attached file, after having unpacked it.